Ubuntu doesn’t detect WiFi Access Point

Recently I came across very different problem when I moved to a place where there was few more access points, my laptop had ubuntu 14.04. [ Note: Users has reported that this works on latest Ubuntu versions also ] $ lsb_release -a I could see lot of other access points in my ubuntu network manager, … Read more

Understanding wireless beacon packet ( captured using pcap API’s )

As per Wikipedia, Beacon frame is one of the management frames in IEEE 802.11 based WLANs. It contains all the information about the network. Beacon frames are transmitted periodically, they serve to announce the presence of a wireless LAN and to synchronise the members of the service set. Beacon frames are transmitted by the access point (AP) in an infrastructure basic … Read more

Wi-Fi Initial Communication between device and access point

Following diagram shows the initial handshaking between the device ( like mobile ) and wireless access-point ( AP ) in open access mode and secured ( e.g. WPA ) mode, Authentication frame ( in open access ): 802.11 authentication is a process whereby the access point either accepts or rejects the identity of a radio … Read more

Simple wifi packet sniffer to capture every packet received on wlan0 interface

$ vim simplesniffer.c [bash] /* Simple Raw Sniffer */ /* Author: Luis Martin Garcia. luis.martingarcia [.at.] gmail [d0t] com */ /* To compile: gcc simplesniffer.c -o simplesniffer -lpcap */ /* Run as root! */ /* */ /* This code is distributed under the GPL License. For more info check: */ /* http://www.gnu.org/copyleft/gpl.html */ #include <pcap.h> … Read more

sniffex – C program to Capture wifi packets using libpcap

libpcap provides functions for user-level packet capture, used in low-level network monitoring. Following program captures the packets from the wireless interface of the device on which the compiled binary will be running. We have compiled this on ubuntu 16.04, and run it on laptop with wifi interface as wlan0, hence it will capture the wifi … Read more

Scan and display all available wireless / wifi networks on ubuntu platforms

LINSSID – linssid is a graphical wireless scanner, LinSSID displays locally receivable 802.11 wireless attach points and ad hoc networks. A table is displayed with various parameters such as MAC address, channel, and signal strength. Graphs are also displayed with signal strength by channel and signal strength over time. LinSSID can be used to measure the … Read more

How to Connect to WiFi Access Point from command line in Linux using nmcli

Following script provides details about how you can connect to WiFi access point using commands in Linux. We have used nmcli command for scanning and connecting to WiFi. nmcli is a command-line tool for controlling NetworkManager and reporting network status. It can be utilized as a replacement for nm-applet or other graphical clients. nmcli is … Read more